The invention relates to a multi-core electric cable, which cable has an outer sheath which surrounds at least one electric pilot line and/or at least one optical fibre line and/or tube therefor in addition to the cores of the cable, and to a cable joint comprising an end portion of such a cable, each of the cores of the cable being electrically connected to respective cores of another electric cable or electric cables within a casing. Particularly, but not exclusively, the invention relates to high voltage oil filled power cables, eg 132 kV power cables, and such joints therefor.
High voltage, eg 132 kV, cable installations including oil filled cables often include low voltage pilot lines for powering switching alarms and oil pressure alarms, for example. Recent developments have resulted in the inclusion of optical fibre communications lines alongside power cables, for example in the same trench as the cables, and the inclusion of optical fibre temperature sensing lines providing a distributed temperature sensing capability for monitoring the temperature of an operating cable along its length, which sensing lines may be taped along or helically around the cable oversheath.